A spine stabilisation system and medical instruments of the type described for holding and manipulating surgical fastening elements are known for example from US 2011/0196426 A1, which also discloses a medical apparatus of the above-described type. This serves to connect together the instruments coupled with surgical fastening elements in the form of polyaxial pedicle screws, in order to orient the holding parts of the fastening elements in a defined manner relative to one another. The instruments are used in particular for minimally invasive securing of the spine stabilisation system to a human or animal spine. Since, in the case of minimally invasive use of the instruments, the distal ends thereof, coupled with the holding parts of the fastening elements, are not visible to a surgeon, but the surgeon has to insert connection elements, for example connecting rods, into corresponding connection element receptacles on the holding parts, in order to secure them thereto, such that the bone screws are held in a defined relative position to one another, it is desirable to know the orientation of the connection element receptacles, even if these are not directly visible. The purpose of the medical apparatus is to simplify insertion of the connection element. In US 2011/0196426 A1 such an apparatus comprises individual members, which are coupled directly together. Each member of the apparatus forms a coupling device, which is in each case temporarily couplable to an instrument.
A disadvantage of the known medical apparatus is in particular that it is awkward to couple to the medical instruments, i.e. in particular such coupling takes a lot of time. Furthermore, parallel alignment of the longitudinal axes of the medical instruments on insertion of the known apparatus cannot be guaranteed with absolute reliability.